This post will be edited as more designs are presented. I will also try to get some OS:VV shots so you can see how the normals turn out.
Edit: I got most of the chassis OS:VV shots.
Edit 2: I got the rest of them, and added #12 to the list.

To add a turret to a chassis is easy, just rename the chassis to something like 'tank.vxl' and the turret 'tanktur.vxl'.

To add a misc. part to the turret or whatever is a little harder but doable. go to the top-to-bottom view of the misc. part and in another window open the turret or chassis and set it to top-to-bottom view, and copy the misc part layer by layer to the other piece. It may be time-consuming and tricky the first time but it works.